mod room_state;
mod server_can;
mod state;
mod user_can;

use std::sync::Arc;

use async_trait::async_trait;
use conduwuit::{Result, err};
use database::Map;
use ruma::{
	EventEncryptionAlgorithm, JsOption, OwnedRoomAliasId, OwnedRoomId, RoomId, UserId,
	events::{
		StateEventType,
		room::{
			avatar::RoomAvatarEventContent,
			canonical_alias::RoomCanonicalAliasEventContent,
			create::RoomCreateEventContent,
			encryption::RoomEncryptionEventContent,
			guest_access::{GuestAccess, RoomGuestAccessEventContent},
			history_visibility::{HistoryVisibility, RoomHistoryVisibilityEventContent},
			join_rules::{AllowRule, JoinRule, RoomJoinRulesEventContent, RoomMembership},
			member::RoomMemberEventContent,
			name::RoomNameEventContent,
			topic::RoomTopicEventContent,
		},
	},
	room::RoomType,
	space::SpaceRoomJoinRule,
};

use crate::{Dep, rooms};

pub struct Service {
	services: Services,
	db: Data,
}

struct Services {
	short: Dep<rooms::short::Service>,
	state: Dep<rooms::state::Service>,
	state_compressor: Dep<rooms::state_compressor::Service>,
	state_cache: Dep<rooms::state_cache::Service>,
	timeline: Dep<rooms::timeline::Service>,
}

struct Data {
	shorteventid_shortstatehash: Arc<Map>,
}

#[async_trait]
impl crate::Service for Service {
	fn build(args: crate::Args<'_>) -> Result<Arc<Self>> {
		Ok(Arc::new(Self {
			services: Services {
				state_cache: args.depend::<rooms::state_cache::Service>("rooms::state_cache"),
				timeline: args.depend::<rooms::timeline::Service>("rooms::timeline"),
				short: args.depend::<rooms::short::Service>("rooms::short"),
				state: args.depend::<rooms::state::Service>("rooms::state"),
				state_compressor: args
					.depend::<rooms::state_compressor::Service>("rooms::state_compressor"),
			},
			db: Data {
				shorteventid_shortstatehash: args.db["shorteventid_shortstatehash"].clone(),
			},
		}))
	}

	fn name(&self) -> &str { crate::service::make_name(std::module_path!()) }
}

impl Service {
	pub async fn get_name(&self, room_id: &RoomId) -> Result<String> {
		self.room_state_get_content(room_id, &StateEventType::RoomName, "")
			.await
			.map(|c: RoomNameEventContent| c.name)
	}

	pub async fn get_avatar(&self, room_id: &RoomId) -> JsOption<RoomAvatarEventContent> {
		let content = self
			.room_state_get_content(room_id, &StateEventType::RoomAvatar, "")
			.await
			.ok();

		JsOption::from_option(content)
	}

	pub async fn get_member(
		&self,
		room_id: &RoomId,
		user_id: &UserId,
	) -> Result<RoomMemberEventContent> {
		self.room_state_get_content(room_id, &StateEventType::RoomMember, user_id.as_str())
			.await
	}

	/// Checks if guests are able to view room content without joining
	pub async fn is_world_readable(&self, room_id: &RoomId) -> bool {
		self.room_state_get_content(room_id, &StateEventType::RoomHistoryVisibility, "")
			.await
			.map(|c: RoomHistoryVisibilityEventContent| {
				c.history_visibility == HistoryVisibility::WorldReadable
			})
			.unwrap_or(false)
	}

	/// Checks if guests are able to join a given room
	pub async fn guest_can_join(&self, room_id: &RoomId) -> bool {
		self.room_state_get_content(room_id, &StateEventType::RoomGuestAccess, "")
			.await
			.map(|c: RoomGuestAccessEventContent| c.guest_access == GuestAccess::CanJoin)
			.unwrap_or(false)
	}

	/// Gets the primary alias from canonical alias event
	pub async fn get_canonical_alias(&self, room_id: &RoomId) -> Result<OwnedRoomAliasId> {
		self.room_state_get_content(room_id, &StateEventType::RoomCanonicalAlias, "")
			.await
			.and_then(|c: RoomCanonicalAliasEventContent| {
				c.alias
					.ok_or_else(|| err!(Request(NotFound("No alias found in event content."))))
			})
	}

	/// Gets the room topic
	pub async fn get_room_topic(&self, room_id: &RoomId) -> Result<String> {
		self.room_state_get_content(room_id, &StateEventType::RoomTopic, "")
			.await
			.map(|c: RoomTopicEventContent| c.topic)
	}

	/// Returns the space join rule (`SpaceRoomJoinRule`) for a given room and
	/// any allowed room IDs if available. Will default to Invite and empty vec
	/// if doesnt exist or invalid,
	pub async fn get_space_join_rule(
		&self,
		room_id: &RoomId,
	) -> (SpaceRoomJoinRule, Vec<OwnedRoomId>) {
		self.room_state_get_content(room_id, &StateEventType::RoomJoinRules, "")
			.await
			.map_or_else(
				|_| (SpaceRoomJoinRule::Invite, vec![]),
				|c: RoomJoinRulesEventContent| {
					(c.join_rule.clone().into(), self.allowed_room_ids(c.join_rule))
				},
			)
	}

	/// Returns the join rules for a given room (`JoinRule` type). Will default
	/// to Invite if doesnt exist or invalid
	pub async fn get_join_rules(&self, room_id: &RoomId) -> JoinRule {
		self.room_state_get_content(room_id, &StateEventType::RoomJoinRules, "")
			.await
			.map_or_else(|_| JoinRule::Invite, |c: RoomJoinRulesEventContent| (c.join_rule))
	}

	/// Returns an empty vec if not a restricted room
	pub fn allowed_room_ids(&self, join_rule: JoinRule) -> Vec<OwnedRoomId> {
		let mut room_ids = Vec::with_capacity(1); // restricted rooms generally only have 1 allowed room ID
		if let JoinRule::Restricted(r) | JoinRule::KnockRestricted(r) = join_rule {
			for rule in r.allow {
				if let AllowRule::RoomMembership(RoomMembership { room_id: membership }) = rule {
					room_ids.push(membership.clone());
				}
			}
		}
		room_ids
	}

	pub async fn get_room_type(&self, room_id: &RoomId) -> Result<RoomType> {
		self.room_state_get_content(room_id, &StateEventType::RoomCreate, "")
			.await
			.and_then(|content: RoomCreateEventContent| {
				content
					.room_type
					.ok_or_else(|| err!(Request(NotFound("No type found in event content"))))
			})
	}

	/// Gets the room's encryption algorithm if `m.room.encryption` state event
	/// is found
	pub async fn get_room_encryption(
		&self,
		room_id: &RoomId,
	) -> Result<EventEncryptionAlgorithm> {
		self.room_state_get_content(room_id, &StateEventType::RoomEncryption, "")
			.await
			.map(|content: RoomEncryptionEventContent| content.algorithm)
	}

	pub async fn is_encrypted_room(&self, room_id: &RoomId) -> bool {
		self.room_state_get(room_id, &StateEventType::RoomEncryption, "")
			.await
			.is_ok()
	}
}